Time cycle controls



Aug. 22, 1961 w. R. KING 2,997,030

TIME CYCLE CONTROLS Filed Jan. 29, 1960 4 Sheets-Sheet 1 INVENTOR Will/am R. King ATTORNEYS Aug. 22, 1961 Filed Jan. 29, 1960 W. R. KING 4 Sheets-Sheet 2 w 6/ 66 67 i; 64 2 Fly-8 5-, 5% 75 g I I )l W g 52 x willy-ll \\\!'\.1.1W/Z//4 y m 48 $9 49 F/ 59 57 55' 55 35 INVENTOR I 37 William R. King ATTORNEYS Aug. 22, 1961 w. R. KING 2,997,030

TIME CYCLE CONTROLS Filed Jan. 29, 1960 4 Sheets-Sheet 3 1 a5 35 J' INYENTOR 1 Will/am R. K/ng &

F fg. 6

BY W

ATTORNEYS w. R. KING 2,997,030

TIME CYCLE CONTROLS Aug. 22, 1961 4 Sheets-Sheet 4 Filed Jan. 29, 1960 W/l/iam INVENTOR R. King ATTORNEYS ire Sttes This invention relates to new and useful improvements in time cycle controls.

One object of the invention is to provide an improved time cycle control or timer which is actuated by pressure so as to permit accurate adjustment of its intervals of operation and reduce the possibility of failure to a minimum.

Another object of the invention is to provide an improved pressure-actuated timer having a pressure-responsive member for controlling the flow of pressure fluid to and from a valve or other mechanism for automatically operating the mechanism at predetermined intervals of time.

A particular object is to provide an improved timer, of the character described, having means operated by actuation of the pressure-responsive member for directing pressure fluid to and from said member and to and from the mechanism whereby the operation of said mechanism is controlled by and in accordance with the actuation of said member.

An important object of the invention is to provide an improved timer, of the character described, having means for controlling the rates of admission and exhaustion of pressure fluid to and from the pressure-responsive member whereby the actuation of said member may be accurately regulated in accordance with selected time schedules.

Another object of the invention is to provide an improved timer, of the character described, wherein the rate controlling means communicates with one side only of the pressure-responsive member whereby the actuation of said member is controlled by the rate of flow of the pressure fluid to and from said one side of said member which permits the interval of actuation in either direction to be varied independently of the interval of actuation of said member in the opposite direction.

A further object of the invention is to provide an improved time cycle control or timer, of the character described, having means for exhausting pressure fluid from the pressure-responsive member to permit closing of a valve and responsive to the pressure of the fluid being controlled by the valve whereby the exhausting means is actuated when the pressure of said controlled fluid becomes excessive.

An object of the invention is to provide an improved timer, of the character described, wherein the admission and exhaustion rates of pressure fluid to and from the pressure-responsive member are controlled by the areas of orifices which are variable to permit adjustment of the intervals of actuation of said member.

A construction designed to carry out the invention will be hereinafter described, together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, wherein examples of the invention are shown, and wherein:

FIG. 1 is a transverse, vertical, sectional View, partly in elevation, of a time cycle control, constructed in accordance with the invention and mounted on a motor valve, with its piston valve lowered to direct pressure fluid to the underside of its lowered diaphragm,

FIG. 2 is an enlarged view, similar to FIG. 1, of the central portion of the control,

atent 2,997,030 Patented Aug. 22, 1961 FIG. 3 is an enlarged, transverse, vertical, sectional view, taken on the line 33 of FIG. 1,

FIG. 4 is an enlarged view, similar to FIG. 1, showing the piston valve raised for directing pressure fluid to the topside of the raised diaphragm,

FIG. 5 is an enlarged, fragmentary, sectional view of the spring-pressed detent holding the piston valve in its lower position,

FIG. 6 is an enlarged, fragmentary, sectional view of a reversed check valve for use with one of the metering valves of the control,

FIG. 7 is an enlarged view, similar to FIG. 3, of a modified control having pressure limit means, and

FIG. 8 is an elevational view showing a pair of check valves for use with the metering valves.

In the drawings, the numeral 10 designates a time cycle control or timer for actuating a motor valve 11 or other mechanism at predetermined intervals. The motor valve 11 is of conventional construction and has its body 12 connected in and communicating with a line 13 for controlling the flow of gas, oil or other fluid therethrough. A seat 14 is for-med in the body 12 for engagement by a valve element 15 on the lower end of a rod or stem 16 which has its upper end connected to a flexible diaphragm or pressure-responsive member 17 mounted in a diaphragm case 18. The diaphragm 17 is constantly urged upwardly to hold the valve element 15 in engagement with the seat 14 by a helical spring 19 confined upon the stem 16 between said diaphragm and an underlying shoulder 20. Although the motor valve 11 is normally closed, it is noted that said valve may be of the normally-open type wherein the spring holds the valve element unseated.

The control '10 includes a diaphragm case 21, having the usual flexible diaphragm or pressure-responsive member 22 mounted therein, which may be connected by a mounting block or fitting 23 to the diaphragm case 18 of the motor valve 12 or other mechanism which is to be actuated by the timer. For conducting gas or other pressure fluid to and from the case 18 above its diaphragm 17, an angular port 24 is formed in the fitting 23 and is connected by a tube 25 to the case 21 above its diaphragm 22. The fitting has another angular port 26 for connecting a lateral pipe 27 to the case 21 below its diaphragm to conduct gas or other fluid pressure to and from the bottom of said case. An axial opening 28 is formed in the top of the case 21 for admitting and exhausting pressure fluid to and from said case above its diaphragm as well as to and from the case 18 above its diaphragm. The diaphragm 22 is reinforced by a pair of overlying and underlying, circular plates 29 which are held in clamping engagement with said diaphragm by nuts or other fasteners 30 having screwthreaded connection with the lower end of an axial rod or stem 31. A helical spring 32 is loosely confined upon the stem above the diaphragm, the upper end of said stem projecting through the opening 28 and having a cylindrical valve 33 slidably confined thereupon.

The valve 33 is of the piston or sleeve type and is reciprocal in a cylinder formed by the complementary bore or chamber 34 of an upright, hollow body 35 which has its lower end secured in the opening 28 (FIGS. 2 and 4). A bottom wall or cross partition 36, having a plurality of openings 37, is provided at the lower end of the piston valve and a helical spring 38 is loosely confined on the stem 31 above the partition by suitable nuts 39. For guiding the stem, an elongated, reduced housing 40 extends axially above and below a cap or plate 41 which closes the upper end of the body 35. The lower end of the housing 40 depends into the piston valve 33 and the internal diameter of said housing is sufiicient to accommodate the spring 38 and nuts 39. A retaining ring 41' for the piston valve may be provided at the lower end of the cylinder 34. The lower portion of the cylinder communicates with an inlet orifice or port 42 which extends laterally through the wall of the body 35 and which is connected by a conductor 43 to a source (not shown) of gas or other fluid under pressure. A similar lateral outlet orifice or port 44 communicates with the upper portion of the cylinder 34. Between the orifices 42 and 44, an orifice or port 45 extends through the wall of the body to establish communication between the medial portion of the cylinder and a lateral pipe 46 which, as will be explained, communicates with the pipe 27.

For sealing off between the piston valve 33 and cylinder 34, O-rings or other seal rings 47 encircle and are carried by the upper and lower ends of said piston valve. An annular, external recess 48 is formed in the piston valve between its ends for constant communication with the medial orifice 45 and communication with the inlet orifice 42 in its lower position (FIG. 2) and with the outlet orifice 44 in its upper position (FIG. 4), whereby said medial orifice communicates with either said inlet orifice or said outlet orifice. The upper end of the piston valve and its upper O-ring 47 are below the outlet orifice when said valve is lowered and its lower end and the lower O-ring 47 are above the inlet orifice when said valve is raised. For locking the piston valve in its lower and upper positions, its recess 48 is formed by a pair of spaced grooves 49 and 50 for coacting with one or more spring-pressed detents 51. As shown in FIG. 5, each detent 51 includes a cylindrical plunger or pin 52 extending through a radial opening 53 in the wall of the body 35 and having a bevelled inner end 54 for engagement with the grooves 49 and 50. An enlarged head 55 is formed on the outer end of the pin 52 and is disposed within the outer end portion 56 of the opening 53 which is of enlarged diameter and has the inner end of a cylindrical sleeve 57 secured therein. The pin is constantly urged inwardly by a helical spring 58 confined in the sleeve 57 between the head 55 of said pin and a screw 59 threaded in the outer end of said sleeve.

When the diaphragm 22 and piston valve 33 are in their lower positions as shown in FIGS. 1 and 2, the diaphragm 17 of the motor valve 11 is held in its upper position by the spring 19 and the valve element 15 is seated to prevent flow through the line 13. The case 18 above its diaphragm is in communication with the outlet orifice 44 through the port 24 of the fitting 23, the tube 25, the case 21 above its diaphragm, the openings 37 of said piston valve, and between the housing 40 and piston valve to the upper portion of the cylinder 34 of the body 35. With the elements in this position, pressure fluid entering the cylinder through the inlet orifice or port 42 and pipe 43 is directed by the recess 48 of the piston valve to the medial orifice 45 and through the pipes 46 and 27 and the port 26 of the fitting 23 to the case 21 below its diaphragm 22 so as tomove said diaphragm upwardly. As the diaphragm approaches its upper position, the spring 32 bears against the partition 36 of the piston valve so as to lift said piston valve (FIG. 4). This upward travel of the piston valve moves its lower seal ring 47 above the inlet orifice 42 and its upper seal rings above the outlet orifice 44, whereby said inlet orifice communicates with the case 21 above its diaphragm and the recess 48 of said piston valve establishes communication between the medial and outlet orifices. The elements remain in this position until the pressure of the fluid becomes suflicient to force the diaphragm 22 downwardly.

With the piston valve in the up position as described, the pressure fluid from the inlet orifice flows from the case 21 through the tube 25 and port 24 to the case 18 above its diaphragm 17 and moves said diaphragm downwardly to open the motor valve 11 when the pressure of said fluid becomes sufiicient to overcome the force of the spring 19. At the same time, the pressure fluid is acting against the upper surface of the diaphragm 22 to move the same downwardly. This downward movement is permitted by the pressure fluid below the diaphragm 22 escaping through the port 26, pipes 27 and 46, medial orifice 45, recess 48 and outlet orifice 44. When the diaphragm approaches its lower position (FIGS. 1 and 2), the downward movement of the stem 31 causes the spring 38 to bear against the partition 36 of the piston valve 33 and lower said piston valve. This movement disposes the rings 47 below the inlet and outlet orifices, whereby the recess 48 establishes communication between said inlet orifice and the medial orifice 45 to direct the pressure fluid to the underside of the diaphragm 22. The outlet orifice again communicates with the case 21 above said diaphragm to exhaust pressure fluid from the case 18 and permit closing of the motor valve 11. The elements remain in this position until the pressure of the fluid becomes suflicient to lift the diaphragm 22. Due to the spring-pressed detent 51 which resists reciprocation of the piston valve, it is noted that snap action is imparted to said piston valve by the compression of the springs 32 and 38. Also, the loose connection between the diaphragm and piston valve provided by the stem 31 permits upward and downward flexing of said diaphragm relative to the piston valve whereby said valve is not reciprocated until said diaphragm approaches its upper and lower positions.

A pair of metering valves 60 and 61 are interposed between the pipes 27 and 46 for controlling the flow of pressure fluid to and from the case 21 below its diaphragm 22 (FIGS. 1, 3 and 4). The valves 60 and 61 are mounted in a rectangular block or valve body 62 which has a transverse port 63 connected to the pipe 46 and communicating with a longitudinal duct or passage 64. A pair of ports 65 communicating with a longitudinal duct or passage 64. A pair of ports 65 communicate with the passages 64 and are connected by a pair of upright conductors 66 and 67 to a rectangular block or fitting 68 having a transverse port 69 connected to the pipe 27 and communicating with the conductors through a longitudinal duct or passage 70. As most clearly shown in FIG. 7, wherein a modification is illustrated, the metering valves are identical except for their metering pins 71 and 72 and orifices 73 and 74. A needle or element 75 of small diameter is carried by the pin 72 for controlling flow through the orifice 74 which is of less diameter than the orifice 73. The orifices are disposed and establish communication between the passage 64 and the ports 65, in which the usual filter screens 76 may be mounted, and are in axial alinement with said ports and with ports 77 above and communicating with said passage.

Each of the metering valves 60 and 61 includes a bonnet 78 screwthreaded in one of the ports 77 and having one of the metering pins 71 and 72 screwthreaded therein so as to depend therefrom through the passage 64 for co'acting with one of the orifices 73 and 74. A packing gland 79 is provided at the upper portion of each bonnet 78 for sealing off around each metering pin. The upper end of each pin projects above the bonnet and has an enlarged, flanged head or cap 80 secured thereto to facilitate turning thereof. A pointer 81 projects radially from the lower portion of each cap 80 for rotation therewith relative to a collar or ring 82 encircling and fastened on each body below the cap to indicate the position of each metering pin relative to its orifice. In order to prevent damaging of the metering pins, a suitable stop 83 may upstand from each indicating collar 82 for engagement by each pointer 81. A check valve 84 is mounted in the conductor 66 to permit flow in only one direction through the larger orifice 73. When the motor valve 11 is of the normally-closed type as shown in FIG. 1, the check valve 84 has an upwardly-directed seat 85 for overlying engagement by a valve ball 86 which is urged downwardly by a helical spring 87 to prevent downward flow. As shown by the numeral 84 in FIG. 6, the check valve is reversed aee'aoso and has a downward-directed seat 85' and an underlying valve ball 86 and spring 87' to prevent upward flow when the motor valve is of the normally-open type.

Although the pressure fluid may flow in either direction through the conductor 67 and orifice 74, the check valve 84 or 84 determines the direction of flow through through the conductor 66 and orifice 73. Due to its larger area, the orifice 73 is adapted to accommodate a greater volume of flow than the orifice 74 so as to cause movement of the diaphragm 22 in one direction in less time than in the other direction. The motor valve 11 is closed for a longer period of time than it is open when the downwardly-seating check valve 84 is used because the area of the orifice 74 is restricted relative to the combined areas of both orifices through which the pressure fluid exhausts from the underside of the diaphragm 22. Of course, the orifices and metering pins may be of the same diameter and the areas of said orifices may be varied by adjustment of the pins. The length of time required for the diaphragm to reach its upper position is determined by the area of the orifice 74, which is controlled by the setting of its metering pin 72, and the motor valve remains closed during such time. As explained hereinbefore, the motor valve does not open until the piston valve 33 is raised to its upper position (FIG. 4) by the diaphragm 22 for directing pressure fluid to the case 18 above its diaphragm 17 to force the valve stem 16 downwardly.

Since the pressure fluid below the diaphragm 22 may flow upwardly through the orifices 73 and 74, comparatively little time is required to exhaust said fluid and permit downward movement of said diaphragm by the pressure fluid thereabove. The areas of both orifices and the setting of their metering pins control the amount of time required for the diaphragm 22 to reach its lower position, and the motor valve remains open until the piston valve 33 is shifted downwardly by said diaphragm to exhaust pressure fluid from the case 18 and permit seating of the valve element 15. Although subject to variation, such time may be of relatively short duration. Whenever it is desirable to keep the motor valve open for a longer period than closed, the reversed check valve 84- of FIG. 6 is substituted for the check valve 84. As shown in FIG. 8, the reversed check valve 84' may be connected in the conductor 67 to prevent upward flow therethrough whereby the pressure fluid below the diaphragm 22 is exhausted through the conductor 66 and its check valve 84 and its rate of exhaustion is controlled solely by the setting of the metering valve 60. When the reversed check valve is mounted in the conductor 67, the metering valve 61 may be opened to a greater extent than the valve 60 in order to keep the motor valve open longer than closed. Since the piston valve is actuated by the diaphragm 22 to control the admission and exhaust of the pressure fluid, the length of time the motor valve is open and shut depends upon the length of time required for said diaphragm to move down and up and the rates of admission and exhaustion are determined and varied by the settings of the metering pins 71 and 72.

Due to the provision of the metering valves 60 and 61 and their metering pins 71 and 72, the interval of actuation of the pressure-responsive member or diaphragm 22 in either direction may be varied independently of the interval of actuation of said diaphragm in the opposite direction. By'properly setting the metering valves, the upstroke as well as the downstroke of the diaphragm can be adjusted between fast and slow movement irrespective of the rate of movement in the opposite direction. Manifestly, accurate adjustment of the intervals of operation of the timer is provided and the possibility of failure is reduced to a minimum. Also, it is pointed out that the actuation of the diaphragm is controlled by the rate of flow of the pressure fluid to and from one side only of said diaphragm.

In some instances, it is desirable or necessary to control the pressure of the fluid in the line 13, such as when said fluid is being utilized to operate a flow valve (not shown) in a well. For preventing the pressure from becoming excessive, a bypass or pressure limit valve 88 is mounted in a modified valve body or block 62 as shown in FIG. 7. The block 62 i similar to the valve body 62, being of greater length, and has the metering valves 60 and 61 mounted in the same manner therein. A duct or passage 89 extends longitudinally of the modified block for establishing communication between one of the ports 65 which is below the orifice 73 of the valve 60, and an upright port 90 in which the bypass valve 88 is mounted. The port 90 communicates with the passage 64, preferably by means of the port 77 above the orifice 73, through a longitudinal duct or passage 91. Between the passages 89 and 91, an upwardly-facing Valve seat 92 is formed in the bypass port for engagement by a complementary valve element 93. The bypass valve includes a bonnet 94 screwthreaded in the upper end of the port 90 and upstanding therefrom for housing the upper portion of the valve element 93 which terminates in an enlarged head 95. A helical spring 96 is confined in the bonnet 94 above the head 95 for urging the valve element downwardly into engagement with the seat 92. When the valve element is unseated, the passages 89 and 91 communicate through the bypass port to permit rapid exhausting of the pressure fluid below the diaphragm 22 and quick closing of the motor valve 11 due to said port being of much larger diameter than the orifices 73 and 74.

As shown by the numeral 98, the valve element 93 has a stem depending from the port 90 through the bottom of the body 62' for actuation by the reciprocal rod 99 of a pressure-responsive member or bellows 100. An upright housing 101 is provided for enclosing the bellows which has an enlarged head 102 at its upper end fastened to the lower end of the rod 99. For contracting and/ or resisting expansion of the bellows, a helical spring 103 is confined above and in engagement with the head 102 by an adjustable follower cap 104 screwthreaded in the upper end of the housing 101. The upper end of the rod 99 projects throughthe cap 104 and has an enlarged tip or head 105 thereon spaced below and in close proximity to the valve stem 98. A tube 106 connects the bellows 100 to an upright port 107 formed in block or fitting 68' and communicating with a conductor 108 which is adapted to communicate with the line 13 downstream of the motor valve 11. The block 68' is of greater length than the block 68, but is otherwise similar thereto and has the port 69 and passage 70 therein for connecting the pipe 27 to the conductors 66 and 67. In the event that the pressure of the fluid in the line 13 downstream of the motor valve exceeds the force required to compress the spring 103, the bellows 100 is expanded to raise the rod 99 and move its tip 105 into contact with the valve stem 98 so as to lift the valve element 93 out of engagement with its seat 92. As explained, the relatively large area of the port 90 permits the pressure fluid, or at least the major portion thereof, to bypass the orifice 73 by means of the passages 89 and 91 so that the motor valve 11 is closed rapidly by the downward movement of the diaphragm 22 and piston valve 33 which permits the escape of the fluid above the diaphragm 17. When the pressure fluid in the downstream portion of the line 13 is reduced sufficiently, such as by bleeding off through the flow valve, the force of the spring 103 returns the bellows to its normal position and lowers the rod out of engagement with the valve stem to permit reseating of the valve element by the spring 96.

It is noted that the bypass valve 88 is operative only when the motor valve 11 is open. Since the valve 88 performs the same function as the metering valve 60, i.e., the exhausting of pressure fluid from below the diaphragm 22, said metering valve may be omitted if it is desired that the motor valve be responsive to the downstream pressure in the line 13. In this event, the motor valve remains open until a predetermined downstream pressure is reached irrespective of the duration of time required for the pressure fluid below the diaphragm 22 to exhaust through the orifice 74 which results in closing off of said motor valve. In addition to limiting the downstream pressure, the bypass valve controls the volume of pressure fluid supplied by the motor valve regardless of whether the valve 60 is employed. Manifestly, the pressure of the fluid may be excessive or fluctuate at its source. Due to the adjustability of the follower cap 1 34 which compresses the spring 103, the pressure required to cause opening of the bypass valve 88 may be varied. It is readily apparent that the metering pins 71 and '72 permit fine adjustment of the eflective areas of the orifices and the rates of flow therethrough. Since these adjustments are positive, the flow rates remain constant until the metering pins are moved whereby the possibility of failure of the timer is reduced to a minimum.

The foregoing description of the invention is explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made, within the scope of the appended claims, without departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent is:

l. A time cycle control for automatically operating a mechanism at predetermined intervals of time including a pressure-responsive member, a chamber communicating with a source of fluid under pressure and with opposite sides of the member and having an outlet, valve means in the chamber and movable between positions wherein the pressure fluid source and outlet alternately communicate with opposite sides of said member whereby the pressure fluid is admitted to one side while being exhausted from the opposite side of said member so as to move said member in opposite directions, the valve means having connection with said member for movement thereby, and means between the chamber and one side of said member for controlling the rates of admission and exhaustion of the pressure fluid to regulate the intervals of actuation of said member.

2. A time cycle control as set forth in claim 1 wherein one side of the pressure-responsive member communicates with the mechanism whereby the pressure fluid is admitted to and exhausted from said mechanism by the valve means.

3. A time cycle control as set forth in claim 1 wherein the mechanism controls the flow of a fluid, the rate controlling means including a valve for exhausting the pressure fluid from the pressure-responsive member to permit movement of said member for operating the mechanism to shut ofl flow of the controlled fluid, and means responsive to the pressure of the controlled fluid for opening the valve to exhaust the pressure fluid.

4. A time cycle control as set forth in claim 1 wherein the rate controlling means includes a pair of adjustable valves for admitting and exhausting the pressure fluid, and means communicating with one of the valves for preventing flow in one direction through said valve.

5. A time cycle control as set forth in claim 1 wherein the rate controlling means includes a pair of orifices, means for varying the areas of the orifices to change the admission and exhaustion rates of the pressure fluid and adjust the intervals of actuation of the pressure-responsive member, and means for preventing flow through one of said orifices in one direction.

6. A time cycle control as set forth in claim 1 including means for loosely connecting the valve means to the pressure-responsive member whereby said member may undergo movement relative to said valve means and whereby said valve means is moved when said member approaches the end of its movement in each direction to reverse the flow of the pressure fluid.

7. A time cycle control as set forth in claim 6 including means for holding the valve means in its positions and resisting movement from such positions.

8. A time cycle control as set forth in claim 6 wherein the connecting means includes resilient means for imparting snap action to the movement of the valve means.

9. A time cycle control as set forth in claim 1 wherein the rate controlling means includes a pair of adjustable valves for admitting and exhausting the pressure fluid, and means communicating with the adjustable valves for preventing flow in one direction through one of said valves and in the opposite direction through the other valve.

10. A time cycle control as set forth in claim 1 wherein the rate controlling means includes a pair of orifices, means for varying the areas of the orifices to change the admission and exhaustion rates of the pressure fluid and adjust the intervals of actuation of the pressure-responsive member, and means for preventing flow in one direction through one of said orifices and in the opposite direction through the other orifice.

11. A timer for controlling the operation of a mechanism including a pressure-responsive member, means for supplying fluid under pressure to opposite sides of the member for imparting movement thereto, valve means in the supplying means and operated by actuation of said member for admitting the pressure fluid to each side of said member while exhausting the fluid from the other side of said member so as to move said member in opposite directions, and means in said fluid supplying means between the valve means and member for controlling the rates of admission and exhaustion of the pressure fluid to regulate the intervals of actuation of said member, one side of said member communicating with the mechanism whereby the pressure fluid is admitted to and exhausted from the mechanism by said valve means.

12. A timer for controlling the operation of a fluid flow control mechanism including a pressure-responsive member, means for suppling fluid under pressure to opposite sides of the member for imparting movement thereto, valve means in the supplying means and operated by actuation of said member for admitting the pressure fluid to each side of said member while exhausting the fluid from the other side of said member so as to move said member in opposite directions, means in said fluid supplying means between the valve means and member for controlling the rates of admission and exhaustion of the pressure fluid to regulate the intervals of actuation of said member, the rate controlling means including a valve for exhausting the pressure fiuid from said member to permit movement of said member for operating the mechanism to shut off flow of the controlled fluid, and means responsive to the pressure of the controlled fluid for opening the valve to exhaust the pressure fluid.

13. A timer for controlling the operation of a mechanism including a pressure-responsive member, means for supplying fluid under pressure to opposite sides of the member for imparting movement thereto, valve means in the supplying means and operated by actuation of said member for admitting the pressure fluid to each side of said member while exhausting the fluid from the other side of said member so as to move said member in opposite directions, and means in said fluid supplying means between the valve means and member for controlling the rates of admission and exhaustion of the pressure fluid to regulate the intervals of actuation of said member, the rate controlling means being between said valve means and one side of said member whereby the rate of admission of the pressure fluid to said one side controls the movement of said member in one direction and movement of said member in the opposite direction is controlled by the rate of exhaustion of the fluid from said one side.

14. A timer for controlling the operation of a mechanism including a pressure-responsive member, means for supplying fluid under pressure to opposite sides of the member for imparting movement thereto, valve means in the supplying means and operated by actuation of said member for admitting the pressure fluid to each side of said member while exhausting the fluid from the other side of said member so as to move said member in opposite directions, means in said fluid supplying means between the valve means and member for controlling the rates of admission and exhaustion of the pressure fluid to regulate the intervals of actuation of said member, the rate controlling means including flow orifices, and means for varying the areas of the orifices to alter the rates of admission and exhaustion of the pressure fluid and adjust the intervals of actuation of said member.

15. A timer as set forth in claim 14 including means for preventing flow through at least one of said orifices in one direction.

16. A time cycle control for automatically operating a fluid flow control mechanism at predetermined intervals of time, including a pressure-responsive member, means for supplying fluid under pressure to opposite sides of the member for imparting movement thereo, valve means in the supplying means and operated by actuation of said member for admitting the pressure fluid to each side of said member while exhausting the fluid from the other side of said member so as to move said member in opposite directions, means in said fluid supplying means between the valve means and one side of said member for controlling the rates of admission and exhaustion of the pressure fluid to said one side of said member to regulate the intervals of actuation of said member whereby the rate of admission to said one side controls movement of said member in one direction and the rate of exhaustion from said one side controls movement of said member in the opposite direction, pressure limit means for exhausting the pressure fluid from said one side of said member to permit movement thereof for operating the mechanism to shut 01f flow of the controlled fluid, and means responsive to the pressure of the controlled fluid for actuating the pressure limit means to exhaust the pressure fluid from said one side.

17. A time cycle control for automatically operating a fluid flow control mechanism at predetermined intervals of time, including a pressure-responsive member, means for supplying fluid under pressure to opposite sides of the member for imparting movement thereto, valve means in the supplying means and operated by actuation of said member for admitting the pressure fluid to each side of said member while exhausting the fluid from the other side of said member so as to move said member in opposite directions, means in said fluid supplying means between the valve means and one side of said member for controlling the rates of admission and exhaustion of the pressure fluid to said one side of said member to regulate the intervals of actuation of said member whereby the rate of admission to said one side controls movement of said member in one direction and the rate of exhaustion from said one side controls movement of said member in the opposite direction, pressure limit means for exhausting the pressure fluid from said one side of said member to permit movement thereof for operating the mechanism to shut off flow of the controlled fluid, and a pressure-responsive member exposed to the pressure of the controlled fluid for actuating the pressure limit means to exhaust the pressure fluid from said one side when the pressure of the controlled fluid exceeds a predetermined amount.

References Cited in the file of this patent UNITED STATES PATENTS 1,731,048 Holmes et al. Oct. 8, 1929 2,450,564 Sacchini Oct. 5, 1948 2,643,644 Way June 30, 1953 2,904,011 Miley Sept. 15, 1959 

